Resilient foraminous paper web forming belt with foramina that close under pressure

ABSTRACT

A paper web forming belt which is composed of a loop of material that is at least partially resilient and which has water drainage openings through it that are closed due to the resilience of the material when the bell is put under pressure. In one form, the belt has a multitude of tabs struck from it which are raised from the plane of the belt so that the tabs are moved back into the plane when the belt is under pressure, and in another form the bell consists of interwoven warp and shute filaments some of which are of elastomeric material so that the interstices between the filaments are closed due to the spreading of the elastomeric filaments when the belt is put under pressure.

- July 10, 1973 K. T. BLEUER RESILIENT FORAMINOUS PAPER WEB FORMLNG BELT WITH FORAMINA THAT CLOSE UNDER PRESSURE Filed Jan. 15, 1970 2 Sheets-Sheet l July 10, 1973 LE R 3,745,066 v RESILIENT FORAMINOUS PAPER WEB FORMLNG BELT WITH FORAMINA THAT CLOSE UNDER PRESSURE Filed Jan. 13, 1970 2 Sheets-Sheet f N is * ENE-i!"- United States Patent RESILIENT FORAMINOUS PAPER WEB FORMING BELT WITH FORAMINA THAT CLOSE UNDER PRESSURE Keith T. Bleuer, 1663 Wilshire Drive NE., Rochester, Minn. 55901 Filed Jan. 13, 1970, Ser. No. 2,552 Int. Cl. D03d 7/00, 15/08; D21f 1/10 U.S. Cl. 162-301 15 Claims ABSTRACT OF THE DISCLOSURE A paper web forming belt which is composed of a loop of material that is at least partially resilient and which has water drainage openings through it that are closed due to the resilience of the material when the belt is put under pressure. In one form, the belt has a multitude of tabs struck from it which are raised from the plane of the belt so that the tabs are moved back into the plane when the belt is under pressure, and in another form the belt consists of interwoven warp and shute filaments some of which are of elastomeric material so that the interstices between the filaments are closed due to the spreading of the elastomeric filaments when the belt is put under pressure.

The invention relates to papermaking machines and more particularly to a web forming belt usable on such machines.

It has previously been proposed in Patent No. 3,224,928, issued on Dec. 21, 1965, to C. A. Lee et al. that a felt be used from the paper stock inlet of a papermaking machine to the drier drum of the machine, and forming of the paper web takes place between a conventional Fourdrinier wire or fabric and the felt. Various dewatering devices are used on the felt for dewatering the felt and the paper web carried thereby in the travel of the felt from the inlet to the drier drum including vacuum boxes, table rolls, a bottom felt held in forceful contact with the web by means of a press, and a pressure roll holding the felt carrying the web in forceful contact with the drier drum and causing the transfer of the web from the felt to the drier drum. A felt is quite conventional and satisfactory for such use between a press roll and drier drum, but a felt does not provide drainage openings through it, so it is not satisfactory for use in dewatering the web just after disposition of the paper stock onto the felt and Fourdrinier fabric. On the other hand, a conventional Fourdrinier fabric would not be useful in place of the felt, as is pointed out in lines 24 to 39, column -6, of the Lee et a1. Patent 3,224,928, particularlysince under pressure it is not capable of releasing water to a great extent and retains water in its interstices, so that effective dewatering of the web cannot take place in the nip of the press roll and the drier drum.

It is accordingly an object of the invention to provide an improved paper web forming belt, and a machine and method for using the belt, the belt to provide a multitude of water drainage openings therethrough in one state of the belt and being capable of substantially closing said openings in another state of the belt particularly when the belt is under pressure. More particularly, it is an object of the invention to provide such a belt that has its water drainage openings substantially closed as it passes through the nip of a pressure roll and a drier drum so as to constitute a substantially closed sheet or belt having no substantial interstices in it as it passes through this m a preferred form, the belt of the invention is a belt formed of resilient sheet material, such as sheet spring steel, having tabs punched therefrom which remain connected on one end to the sheet and which are raised in 3,745,066 Patented July 10, 1973 "ice the punching operation to remain raised with respect to the sheet to provide water drainage openings beneath them to drain water from the paper sheet being formed and which, due to the resilient nature of the sheet, are pushed back into the plane of the sheet by the force exerted by the pressure roll on the drier drum as the belt passes through the nip of the pressure roll and drier drum, so that quite complete dewatering of the paper web takes place in the nip of the pressure roll and drier drum. In another preferred form, the belt of the invention is made up of interwoven shute and warp filaments and most of these filaments are of elastomeric material so that they spread sideways when the belt is put under pressure and so that in doing so they substantially close the interstices between the filaments.

The invention consists of the novel methods, constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above-stated objects, and such other objects, as will be apparent from the following description of preferred forms of the invention, illustrated with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic illustration of a papermaking machine of the invention and utilizing the foraminous w eb forming belt of the invention;

FIG. 2 is a fragmentary plan view of the belt;

FIG. 3 is a sectional view taken on line 3--3 of FIG. 2, with tabs of the belt extending upwardly out of the plane of the belt;

FIG. 4 is a view similar to FIG. 3 but with the tabs being forced down into the plane of the belt due to force exerted on the belt;

FIG. 5 is a sectional view taken on line 55 of FIG. 4;

FIG 6 is a fragmentary plan view of a modified form of the belt;

FIG. 7 is a fragmentary plan view of another modified form of the belt;

FIG. 8 is a sectional view taken on line 8-8 of FIG. 7;

FIG. 9 is a fragmentary plan view of another modified form of the web forming belt of the invention;

FIG. 10' is a sectional view taken on line 10-40 of FIG. 9; and

FIG. 11 is a schematic illustration of another type of papermaking machine with which the illustrated web forming belts may be used.

Like characters of reference designate like parts in the several views.

Referring now to FIG. 1 of the drawings, the embodiment of the invention therein illustrated may be seen to comprise an endless belt or loop of web forming fabric or Fourdrinier wire 10 which is disposed about rolls 11, 12, 13, 14, 15 and 16. The fabric 10 is a conventional paper web forming fabric for use in Fourdrinier machines made up of interwoven warp and shute strands for providing drainage openings therebetween through which water may drain from dilute paper stock applied on the fabric. The strands may be either metal or may be of synthetic material in accordance with well known practice. The roll 11, which is relatively large in diameter in comparison with the other rolls, may be termed a breast roll; the roll 12 is a conventional table roll having both ends fixed; and the roll 13 is on an end of the loop opposite the breast roll 11 having the position of a conventional couch roll. The roll 14 may be used as a stretch roll with suitable conventional mechanism (not shown) for simultaneously adjustably moving both ends of the roll for maintaining the fabric taut about the rolls. The roll 15 is a conventional guide roll having one end fixed and the other movable, and any suitable conventional apparatus (not shown) may be connected with the movable end of the roll 15 so that the roll 15 functions to maintain the fabric loop travelling in substantially the same path about the rolls supporting the fabric. The roll 16 is a conventional turning roll for the fabric having both ends of the roll fixed. One or more of the fabric supporting rolls, such as the breast roll 11, may be driven for the purpose of driving the fabric 10 so that its upper pass between the rolls 11 and 13 moves toward the latter roll. The roll 11 may be solid or may be of a conventional open type.

An upper foraminous paper web forming belt 24 is disposed about rolls 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, and 36. This belt is of a type to be subsequently described that is initially open when paper stock is disposed thereon but is closed when a force normal to the plane of the belt is applied to the belt, so that thorough dewatering of the paper web can take place under these conditions. The roll 25 may be either solid or open and has a nip with the breast roll 11, preferably with a slight clearance, and may be termed a slice roll. The rolls 26 and 25 have a lower pass of the belt 24 extending between them, and the roll 25 depresses the belt 10 adjacent the roll 11 so that an upper pass of the belt 10 and the lower pass of the belt 24 extend approximately horizontally and in substantial contact. The roll 27 constitutes one roll of a main press 37, which also includes another roll 38 having a nip with the roll 27. A bottom felt 39 extends between the rolls 27 and 38 along with the belt 24. The roll 38 is a conventional press roll.

The rolls 28, 29, 31, 32, 34 and 36 are simple turning rolls fixed on both ends. The roll 30 is a pressure roll held forcefully against a Yankee drier drum 41 to have a pressure nip therewith. The roll 33 is a conventional guide roll having one end fixed and the other end movable under the control of any suitable control mechanism (not shown) for maintaining the belt 24 travelling in a predetermined path about the rolls supporting the belt. The roll 35 is a conventional stretch roll having both ends simultaneously adjustably movable by suitable adjusting mechanism (not shown) for maintaining the loop 24 taut about the rolls supporting the loop. One or more of the rolls supporting the belt 24 is driven to thereby move the belt in the direction indicated by the arrows. As will be hereinafter described more in detail, dilute paper stock is provided to the nip between the rolls 11 and 25, and a paper web W is formed on the fabric 10 and travels between the passes of the belts 10 and 24 between the rolls 25 and 26 and thereafter travels on the underside of the belt 24, through the main press 37, and over the rolls 28, 29 and 30 to the drier 41.

A stock inlet 71 is provided for discharging paper stock directly into the nip between the rolls 11 and 25 and into the nip of the belts 10 and 24 extending about these rolls. The inlet 71 may be of the type having two adjacent spaced parallel plates 73 carrying paper stock between them and directing the stock into the slight gap between the rolls 11 and 25; and, more particularly, the inlet may be similar to the inlet 71 disposed in the patent to J. Loynd, No. 3,378,435, issued on Apr. 16, 1968.

The bottom felt 39 is supported by rolls 58, 59, 60, 61, 62 and 63 in addition to the roll 38. The rolls 58 and 60 have a nip between them through which the felt 39 passes, and both of them are solid and a nip pressure is maintained between them, so that the rolls function as a wringer 64 for the felt.

The drum 41 is a conventional Yankee type drier to which steam under pressure is supplied for drying the paper web W. A doctor blade 65 is held in forceful contact with the external surface of the drier 41 by any suitable conventional mechanism, so that the blade is effective for the purpose of doctoring off the web W which is formed by the papermaking machine and is dried by the drier 41. Any suitable takeup and storing apparatus may be provided for the paper web W as it comes from the Yankee drier 41, such as a reel 66. The drum 41 is preferably directly driven from any suitable prime mover (not shown).

Conventional apparatus is provided for collecting so called white water draining through the forming belts 10 and 24 from the web W being formed between the belts, adding fresh stock, and pumping the mixture of white water and fresh stock to the inlet 71.

Various appurtenances are used in connection with the belts of the machine, such as for cleaning them or for dewatering purposes. A doctor blade 78 is disposed beneath the slice roll 25 for downwardly directing water that is thrown from the breast roll 11, and vacuum boxes 79 and 80 are disposed above and below the passes of the belts 10 and 24 between the rolls 25 and 26 for dewatering the paper web between these passes of the belts. Vacuum boxes 86 and 87 are disposed above the belt 24 in its pass between the rolls 26 and 27 for dewatering the belt 24 and the web W carried by the belt. A vacuum box 88 is disposed on the outer surface of the belt 24 and extends slightly into the nip of the roll 30 and drum 41.

In operation of the papermaking machine as so far described, a fiber water mixture is supplied to the stock inlet 71, and this mixture passes onto the web forming regions of the belt 10 and belt 24 between rolls 11 and 25. The belts 10 and 24 are in motion, with the belts moving from the rolls 11 and 25 toward the rolls 13 and 26, and the stock deposited on the web forming regions of belts 10 and 24 between rolls 11 and 2'5 results in the paper web W with white water draining through both of belts 10 and 24. The inlet 71 in conjunction with the belt 24 carried by the slice roll 25 functions as a pressure forming type of inlet in which an enclosed flow conduit is disposed to apply paper stock directly to a restricted area Fourdrinier wire region, the downstream end of which is defined and is substantially sealed with respect to the forming wire by a slice on the discharge end of the conduit. The slice in this case is formed by the rotating slice roll 25 together with the belt 24 that extends around the roll 25 and travels with it and which substantially seals the inlet 71 with respect to the wire 10. In a machine of this type, during the web forming operation, the stock constitutes a confined relatively high energy flowing stream which is under substantial hydraulic pressure so that a large portion of the water is thereby forced through the belts 10 and 24 in the web forming regions at a relatively high rate.

The resulting paper web W passes between the rolls '11 and 25 and into a sandwich formed by the horizontal passes of the belts 10 and 24 between the rolls 11 and 13. White water continues to drain through the fabric 10 and belt 24 as the web moves with the belts 10 and 24 toward the rolls 13 and 26 to further dewater the web, and dewatering is increased by the action of the table roll 12 and the vacuum boxes 79 and 80 in accordance with well known principles of operation of such devices. The web W separates from the fabric 10 and remains on the lower side of the belt 24 as the belts 10 and 24 separate at the roll 26, which thus functions as a pickup roll; and the web W passes with the belts 39 and 24 through the main press 37 formed by the rolls 27 and 28. The vacuum boxes 86 and 87 help in dewatering the web W carried on the lower surface of belt 24 as they pass on to the press 37.

The main press 37' wrings water from the belt 24 and the web W as they pass through the press. The bottom felt 39 also absorbs water from web W which is removed from the felt '39 by the wringer rolls 58 and 60 as the felt continues its travel, so that the felt 39 is presented at the main press 37 in a relatively dewatered condition.

The web W remains on the lower surface of the belt 24 as it passes from the main press 37 over the rolls 28, 29 and 30. The pressure roll 30 presses the web W against the drier 41, and water is expressed from the web W in the nip between the roll 30 and drier 41 due to the force exerted on the belt 24 in this nip, and this water is taken up particularly by the vacuum box 88 which extends slightly into the nip of the roll 30 and drier 41 on the exterior side of the belt 24. The web W transfers from the belt 24 on to the drum 41 at the nip between the pressure roll 30 and the drum and is dried by the drum as it roates. The doctor blade 65 crepes the web from the drum, and the dried web is wound on to the reel 66.

The belt 24 may be of the type shown in FIGS. 2-5 and may be made of a sheet 90 of resilient sheet material, such as spring steel, which is in the form of an endless loop. Tabs 91 are struck or punched out of the sheet 90, and each of these tabs comprises a base portion 91a and a terminal portion 91b, both of which are in the plane of the sheet 90, and a raised portion 91c. Since the tabs in general curve outwardly out of the plane of the sheet 90 when there is no substantial pressure or force on the sheet 90, each of the tabs 91 leaves an opening 92 in the sheet 90 which is longer than the tab 91. The belt 24 travels about its supporting rolls 25-36 in the direction indicated by the arrow A in FIG. 2, and the side 90a of the belt 24 that is exposed in FIG. 2 and is the upper side in FIG. 3 is preferably that side which carries the web W. Since the portions =9-1c of the tabs are out of the plane of the sheet 90, the tabs 91 provide water drainage openings beneath them so that white water may drain through belt 24 to help to form the web W. When the belt 24 travels through the nip between the press roll 30 and the drier drum 41, the tabs 91 are thrust back into their respective openings 92 in the sheet 90 against the inherent resilience of the tabs, since the tabs 91 as well as the rest of the sheet 90 are of spring material, so that the sheet is substantially again in a uniform thickness, uniplanar non-perforate condition as shown in FIGS. 4 and 5; and the belt 24 thus constitutes a single uniform thickness belt or sheet as it passes through the nip between the roll 30 and drum 41 having no interstices in which water may remain that may be reabsorbed into the web W as it transfers from the belt 24 to the drier drum 41. In this connection, it may be noted that both the drum 41 and roll 30 both preferably have uniform, non-perforate outer surfaces; and there is no retention of water on these surfaces either, which may be reabsorbed by the Web W as it leaves the belt 24 and transfers to the drum 41. The web W therefore is drier and more thoroughly dewatered as it is applied onto the surface of the drum 41 than would be the case if the belt 24 were a conventional Fourdrinier fabric made up of warp and shute filaments having permanent interstices between them. It will be noted that the base portions 91a lead the terminal portions 910 in the direction A, and therefore there is no tendency for the tabs 91 to buckle as they pass through the nip between the roll 30 and drum 41.

The form of the belt 24a shown in FIG. 6 is substantially the same as that in FIGS. 2-5 except that the spring tabs 93 struck out of the resilient sheet 90b do not extend exactly in the direction of the arrow A denoting the direction in which the belt 24a moves but rather extend at approximately 4 5 degrees with respect to the direction A. Each of the tabs 93 is punched from the sheet 90b leaving a corresponding opening 94 in the sheet into which each of the tabs 93 return as the tabs pass through the nip of the roll 30 and drum 41.

In the form of the belt 24b shown in FIGS. 7 and 8, the tabs 95 corresponding to the tabs 91 are tapered, having a broader base portion 95a than a terminal portion 950. The tabs 95 are struck from a sheet 90c of spring material providing openings 96 in the sheet 90c so as to constitute spring tabs that with no pressure on them extend out of the plane of the sheet 900 but which re-enter the plane of the sheet when they pass between the roll 39 and drum 41. The tabs 95 preferably have fillet openings 97 at their base ends 95a, and they also have outwardly flaring side edges 95d and 95:: so that as they move outwardly out of their corresponding openings 96 in the sheet 90c they provide gaps sooner between the tabs and the sides of the openings 96 to allow the escape of any paper fibers 6 that may have been caught between the tabe and the edges of the openings 96.

The form of the belt 24c illustrated in FIGS. 9 and 10, which is in the form of a fabric and may be used instead of belt 24, comprises a plurality of relatively small diameter, uncompressible filaments and 101. The filaments 100 may be termed warp filaments and extend in the direction A, which is that direction in which the fabric 240.

moves on its supports rolls 25-36, and the filaments 101 may be termed shute filaments. The belt 240 also includes relatively large diameter, compressible filaments 102 and 103. The filaments 102 extend in the direction A and may be termed warp filaments, and the filaments 103 may be termed shute filaments. In the form of the belt 24c illustrated, there are four filaments 102 for each filament 100, and there are four filments 103 for each filament 101; but there may be one, less than one, or a plurality of the large size filaments 102 and 103 for each of the small size filaments 100 and 101. The illustrated form of the belt 240 is a plain weave with each warp filament passing alternately over and under shute filaments, but it is understood that other weaves could just as well be used instead. It is desirable, as will hereafter appear, that there be the smaller filaments 100 in the wrap direction, but the smaller shute filaments 101 could be omitted if desired, although it is preferred that they be included.

The small diameter filaments 100 and 101 are relatively not extensible and are of high strength, relatively noncompressible material such as metal, bronze or steel, for example. The filaments 100 annd 101 may also be of synthetic material, for example, nylon. Nylon is a well known polyamide synthetic fiber which has excellent strength and yet is bendable, and it can be woven or otherwise processed into a fabric which is suitable for use as a forming carrier. It will be apparent that other materials, particularly in the synthetic fiber field such as polyester fibers sold under such trademarks as Dacron, acrylic fibers sold under such trademarks as Orlon, and Dynel, and vinyl derivative fibers sold under such trademarks as Saran may also be used. The latter types of materials have been suggested for usage in web forming belts in the patent to C. A. Lee, No. 3,041,235, issued on June 26, 1962.

The large filaments 102 and 103 each have a diameter greater than the distance a which is that thickness at the crossing of two of the small diameter filaments 100 and 101, and the filaments 102 and 103 are of elastomeric material, such as natural or synthetic rubber. Some synthetic plastics of the poly types have about the same resilience and ability to distort under pressure as rubber and are thus also of such elastomeric material. Such elastomeric material does not have much strength lengthwise, and therefore the warp filaments 100 are preferably used so that substantial tension may be put on the belt 240 lengthwise about the supporting rolls 25-36. The shute filaments 101 are also preferably used to provide stability to the belt 24c; and, in this connection, each of the filaments 100 and 101 is preferably arched as at 100a in its portion passing over or under another filament 100 and 101 to provide stability to the fabric. Also, whether the filaments 100 and 101 are metal or of synthetic material, they may be welded together at the cross over places for the purpose of stability. The methods of making such Welds are conventional.

Since there is a spacing between the filaments 100-103 as shown in FIG. 9, the fabric of FIG. 9 provides water drainage openings through the fabric in the same manner as does a conventional Fourdrinier fabric, and water drains through the belt 240 in the same manner for dewatering the web W. When the fabric 240 passes between the roll 30 and the drum 41, the fabric is compressed thereby; and the large diameter filaments 102 and 103 expand sidewardly or in the plane of the belt 24c so that they substantially fill up the interstices in the belt 24c. The belt 240 thus presents substantially the same unbroken sheet,

7 free of interstices, as do the belts 24, 24a and 24b as the latter pass through the nip of the roll 30 and drum 41, so that the web W is dewatered to a much greater extent than would be the case if a conventional Fourdrinier fabric were used instead of the belt 240.

In order for the filaments 102 and 103 to be compressed for this action, they should be of greater diameter than the thickness to which the relatively dense filaments 100 and 101 may be compressed to (which is approximately the thickness a). In the event theshute filaments 101 are omitted; in this case, the filaments 102 and 103 should have a diameter greater than the diameter of the filaments 100, since this is approximately the base thickness to which the fabric may be compressed between the roll 30 and drum 41.

The belts 24, 24a, 24b and 240 are useful in types of papermaking machines other than of the pressuure forming type; and one of the non-pressure forming type is shown in FIG. 11. The papermaking machine is provided with a headbox 110 adapted to discharge stock of suitable consistency containing fibers for making paper onto continubus forming belt 24 at a breast roll 111. The forming belt 24 is supported to receive stock discharged from the headbox in a continuous stream and is normally driven at a selected uniform rate.

After the stock has been discharged onto the belt 24, the latter permits sufficient liquid to drain so that a web 117 begins to form in the well known manner. As shown in the drawing, it may be desirable to support the forming belt 24 by one or more table rolls 116 r suction boxes (not shown) to facilitate draining and ultimately the formation of the web. At a sufiicient distance away from the headbox for the web 117 to reach a plastic state, as distinguished from the liquid state of the stock, the forming belt 24 and the Web pass through a resilient pressure nin 118.

Resilient pressure nip 118 is formed by rolls 119 and 120. It may be desirable to contact the exposed face of web 117 with a belt 121, shown by broken lines. The belt 121 may be a conventional felt. It may also be desirable to provide roll 119 with a rubber cover (not shown).

The forming belt 24 nd the web 117 are subjected to pressure by the action of the resilient nip 118, and water is removed.

Belt 24 and web 117 progress from the resilient pressure nip 118 into contact with the drier drum 124, and the belt 24 is held in forceful contact with the drum 124 by pressure roll 123 in the same manner that the roll 30 is effective for this purpose; and the belt 24 is effective in the same maner as above described to allow effective de watering to occur at the nip of pressure roll and drier drum. The carrier 24 is returned to the inlet 110 by means of rolls 126, and web 117 continues around the drier 124 for almost a complete revolution, and a doctor knife 128 may be used for creping the web from the drum. Although the belt 24 is mentioned above in connection with the FIG. 11 machine, it is to be understood that the belts 24a, 24b, or 240 could be used instead of belt 24.

Using the machine shown in FIG. 11, the belts 24, 24a and 24b are preferably used with the face 90a, and the faces of sheets 90b and 900 visible in FIGS. 6 and 7, up at the places of the belts onto which the paper stock is spouted by the inlet 110 (these faces are preferably underneath the portions of the belts 24, 24a, and 24b which extend between the rolls 25 and 26 in the first form of machine).

The use of the belts 24, 24a, 2412, or 24c allow the same belt to be used for draining white water from the paper stock as is used for transporting the paper web through the nip of a pressure roll and drier drum with effective dewatering in this nip. The conventional intermediate felt section between a Fourdrinier wire and drier drum may thus be dispensed with, so that the paper machine as a whole is simpler and thus of more economical construction.

It is understood that the invention is not to be limited to the specific constructions and'arrangements shown and described, except only insofar as the claimsmay be so limited, as it will be apparent to those skilled in the art that changes may be made without departing fromthe principles of the invention.

I claim:

1. An endless paper web forming belt comprising a plurality of spaced warp filaments that extend longitudinally of the belt and a plurality of spaced shute filaments that extend crosswise of the belt to provide foramina through the belt, at least some of said filaments being made of elastomeric material and said elastomeric filaments being so closely spaced with respect to adjacent filaments and being of such large cross sectional size so that the elastomeric material filaments deform and spread sideways in the plane of the belt when force normal to the belt is applied thereto to substantially close said foramina and thereby squeeze out any water in the foramina.

2. An endless web forming belt according to claim 1, said elastomeric filaments including some of said warp filaments, said belt including also some relatively small diameter, relatively inextensible filaments in the plane of the belt and extending in the warp direction for limiting the longitudinal extension of the belt.

3. An endless web forming belt according to claim 2, some of said shute filaments also being of elastomeric material.

4. An endless web forming belt according to claim 3 and also including some relatively small diameter, relatively inextensible filaments extending crosswise of the belt.

5. An endless paper web forming belt comprising a plurality of spaced warp filaments that extend longitudinally of the belt and a plurality of spaced shute filaments that extend crosswise of the belt to provide water draining foramina through the belt, some of said filaments being elastic and others of said filaments being substantially inextensible compared to said elastic filaments, said relatively inextensible filaments extending in the belt in the same direction as said elastic filaments and being of such small thickness in the direction normal to the plane of the belt with respect to said elastic filaments so that said elastic filaments deform and spread sideways in the plane of the belt when force normal to the plane of the belt is applied thereto to substantially reduce the areas of said foramina and squeeze out water in the foramina.

6. An endless paper web forming belt as set forth in claim 5, each of said substantially inextensible filaments being smaller in thickness than said elastic filaments in the direction normal to the plane of the belt.

7. An endless web forming belt according to claim 5, said elastic filaments including some of said warp filaments and said substantially inextensible filaments including others of said warp filaments whereby to limit the longitudinal extension of the belt.

8. An endless web forming belt according to claim 7, some of said shute filaments also being elastic.

9. An endless web forming belt according to claim 8, some of said shute filaments also being substantially inextensible compared to said elastic shute filaments.

10. An endless web forming belt according to claim 9, each of said elastic filaments being of a thickness greater than the thickness of a pair of said warp and shut substantially inextensible filaments in the direction normal to the plane of the belt at the crossing point of the pair of filaments.

11. In combination, an endless belt, a plurality of rolls for moveably supporting said belt, a rotatable drier drum, said belt being formed of a plurality of spaced warp filaments that extend longitudinally of the belt and a plurality of spaced shute filaments that extend crosswise of the belt to provide foramina through the belt through which water may drain from paper stock placed on the belt so as to form a paper web on the belt, one of said rolls being held forcefully against said drier drum so as to have a pressure nip therewith to cause the transfer of the paper web from said belt to said drum, some of said warp filaments being elastic and others of said warp filaments being substantially inextensible compared to said elastic filaments and being of smaller thickness in the direction normal to the plane of the belt than said elastic filaments so that said elastic filaments deform and spread sideways in said pressure nip to substantially reduce the areas of said foramina and squeeze out water in the foramina and 1 the substantially inextensible filaments limit the longitudinal extension of the belt.

12. In combination, as set forth in claim 11, some of said shute filaments also being elastic and some of said shute filaments also being substantially inextensible compared to said elastic shute filaments and being of smaller thickness in the direction normal to the plane of the belt than said elastic shute filaments.

13. In combination, an endless belt, a plurality of rolls for moveably supporting said belt, a rotatable drier drum, said belt having a multitude of foramina therethrough for draining water from the paper stock placed thereon so as to form a paper web on the belt, one of said rolls being held forcefully against said drier drum so as to have a pressure nip therewith to cause the transfer of the paper web from said belt to said drum, and means for substantially closing the areas of said foramina as they pass through said nip, said area closing means including parts of said belt made from resilient material, the pressure force on said belt in said pressure nip being sufficient so as to substantially deform said resilient material to thereby substantially close said foramina as aforesaid, said belt comprising a plurality of spaced warp filaments that extend longitudinally of the belt and a plurality of spaced shute filaments that extend crosswise of the belt to provide said foramina through the belt, at least s-ome of said filaments being made of elastomeric material and said elastomeric filaments being so closely spaced with respect to adjacent filaments and being of such large cross sectional 10 size so that the elastomeric material filaments deform and spread sideways in the plane of the belt when force normal to the belt is applied thereto to substantially close said foramina as aforesaid and thereby squeeze out any water in the foramina.

14. In combination, as set forth in claim 13, said elastomeric filaments including warp filaments extending longitudinally of said belt and said belt also including filaments which are of substantially smaller diameter and are less extensible than said elastomeric filaments and extending in the warp direction for limiting the extension of the belt longitudinally.

15. In combination, as set forth in claim 13, the combination including a second foraminous belt, means for supporting said second belt so that it has a pass extending along a pass of said first named belt, and a stock inlet for depositing paper stock between said passes whereby the paper stock drains through both of said belts and is transported to said drier drum on said first named belt for transfer onto said drier drum.

References Cited UNITED STATES PATENTS 1,925,917 9/1933 Chalon 162-358 X 3,207,657 9/1965 Wagner et al 162-361 X 3,162,567 12/1964 Heller 162-348 3,224,928 12/1965 Lee et al. 162-2114 3,207,659 9/1965 Wagner 162-348 X 3,150,037 9/1964 Lee 162-348 X 2,969,581 l/l961 Bischoff 139-425 X 3,214,331 10/1965 Wicker 162-358 S. LEON BASI-IORE, Primary Examiner R. H. TUSHIN, Assistant Examiner US. Cl. X.R.

139-420; 161-110; 162-203, 303, 348, 359, Dig. 1 

